Calculating Progressed House Cusps (


Well-known member
I love but the calculations it gives me, especially in regards to progressed house cusps, are often a 1-2 degree difference over the other computer sources I use (Solar Fire software and the Astro Gold iPhone/iPad app).

In dealing with predictive work, a 1-2 degree difference for house cusps is huge because it is the difference between a house cusp changing signs this year or next year.

I would love to hear verification from people on which is the most accurate from various sources. Thank you!


Well-known member
There is nothing like good old-fashioned personal experiences to help answer these questions...

So I think the answer to my own question is that's progressed chart calculation is the most accurate because I have already felt a large paradigm shift that matches the 9th house cusp progressing into a new sign.

Astro Gold (Solar Fire's iPhone/iPad app) calculates the 9th progressing into a new sign next January (2018), but's progressed chart has already shifted the 9th into the next sign.


Well-known member

I think you could check these two possible "issues":

1) Exact geographic coordinates of your birth city.
---, Solar Fire and the Astro Gold may be using different coordinates of your birth city (do they use city center coordinates?; do they use hospital coordinates? and which hospital do they use, if there are more hospitals in your city? ...)
It may cause small differences sometimes, especially at house cusps.

2) Ecliptic (Longitude) vs Equatorial (Right ascension) system:
There are several options of calculation progressed angles/house cusps.
Some astrologers/softwares prefer to derive angles along the ecliptic coordinates (Longitude);
Some astrologers/softwares prefer to derive angles along the equator coordinates (Right ascension)

Difference between Longitude and Right ascensin is very often cca. 1-2° Degree ... which might be also your case.

I found, that SOLAR FIRE should have this setting:
Go to Preferences > Edit Settings. Select the Progs/Dirns tab. Under Chart Angle Progression select SA in Long.


I will tell i know and have done years and years on exact cusp numbers study try koch for chart its by far most accurate!!!